JP6796214B2 - Turbine and turbocharger equipped with it - Google Patents

Description

The present disclosure relates to a turbine and a turbocharger equipped with the turbine.

Generally, in an internal combustion engine for marine use, automobiles, etc., the exhaust energy is used to rotate a turbine impeller, and a compressor impeller provided coaxially with the turbine impeller is rotated to increase the intake pressure of the internal combustion engine and internal combustion. Turbochargers are known to increase the power of the engine.

Patent Document 1 and Patent Document 2 disclose a turbocharger including a turbine housing provided so as to cover the turbine impeller.

Japanese Unexamined Patent Publication No. 2013-174129 Japanese Unexamined Patent Publication No. 11-2298887

In recent years, in the field where miniaturization of internal combustion engines is promoted, miniaturization of the turbocharger itself is also required accordingly. Since the turbine housing is usually molded by casting, the feasibility of the core forming the inner wall shape of the turbine housing is important. However, if the turbocharger is miniaturized due to recent demands, it becomes difficult to mold the core forming the inner wall shape of the turbine housing, and the feasibility of the core may decrease. In particular, since the throat portion of the scroll flow path is narrower than other portions, the feasibility of the core due to the miniaturization of the turbocharger tends to be a problem.

Therefore, an object of at least one embodiment of the present invention is to provide a turbine housing capable of improving the moldability of the inner wall shape of the turbine housing by casting while promoting the miniaturization of the turbocharger in view of the above circumstances. It is to provide a turbocharger.

(1) The turbine according to some embodiments of the present invention is
Turbine impeller and
A turbine housing that is provided so as to cover the turbine impeller and forms a scroll flow path through which exhaust gas flows inside.
A throat forming portion provided as a separate member from the turbine housing,
With
The throat forming portion is provided in the axial direction so as to face the portion of the turbine housing that forms the shroud side wall surface of the throat portion of the scroll flow path, and forms the hub side wall surface of the throat portion.

According to the configuration of (1) above, in the throat portion of the scroll flow path whose width in the axial direction is narrower than that of other portions, the hub side wall surface facing the shroud side wall surface is throated as a member different from the turbine housing. It can be formed by the forming part. Therefore, even when the turbine is miniaturized, it is possible to facilitate the molding of the core forming the inner wall shape when casting the turbine housing, and it is possible to improve the moldability of the inner wall shape of the turbine housing.

(2) In some embodiments, in the configuration of (1) above,
The throat forming portion is
A first portion of the throat portion forming the hub side wall surface and
A second portion that faces the back surface of the turbine impeller on the inner side in the radial direction with respect to the first portion.
including.

According to the configuration of (2) above, since the throat forming portion includes the first portion forming the hub side wall surface of the throat portion and the second portion facing the back surface of the turbine impeller, the throat forming portion is formed on the back surface of the turbine impeller. It can also be used as a part facing the. With such a simple structure, the establishment of the core in the casting of the turbine housing can be improved, and the heat dissipation of the exhaust gas on the back surface side of the turbine impeller can be suppressed.

(3) In some embodiments, in the configuration of (1) or (2) above,
The throat forming portion includes a plate member forming the hub side wall surface of the throat portion.

According to the configuration of (3) above, since a plate-shaped member can be adopted for the throat forming portion, a sheet metal product (for example, a commonly used back plate or the like) is used to form the hub side wall surface of the throat portion. Can be done.

(4) The turbine according to some embodiments of the present invention is
Turbine impeller and
A turbine housing provided so as to cover the turbine impeller and having an outlet portion for exhausting exhaust gas after passing through the turbine impeller.
A heat shield portion located on the side opposite to the outlet portion in the axial direction is provided with at least one of the turbine impeller or a scroll flow path communicating with the turbine impeller.
The heat shield is
The first heat shield and
A second heat shield plate portion that is at least partially arranged with a gap between the first heat shield plate portion and the first heat shield plate portion.
including.
In addition, either one of the "first heat shield plate portion" and the "second heat shield plate portion" constituting the heat shield portion constitutes the "throat forming portion" in the above (1) to (3). May be good.

The configuration of (4) above is different from the above-mentioned problem (improvement of moldability of the inner wall shape of the turbine housing), and is for solving the problem of improving the efficiency of the turbine by suppressing heat dissipation of exhaust gas. ..
That is, according to the configuration of (4) above, the heat shield portion including the first heat shield plate portion and the second heat shield plate portion sandwiches at least one of the turbine impeller and the scroll flow path and serves as an outlet portion in the axial direction. Since it is located on the opposite side, heat dissipation of exhaust gas flowing through the scroll flow path and the turbine impeller can be suppressed. Further, an intermediate layer is formed by sandwiching a gap at least partially between the first heat shield plate portion and the second heat shield plate portion, and heat is transferred from one heat shield plate portion to the other heat shield plate portion. Can be suppressed. Therefore, the efficiency of the turbine can be improved by suppressing the exhaust gas from radiating to the outside.

(5) In some embodiments, in the configuration of (4) above,
A bearing housing provided in the axial direction opposite to the outlet portion of the turbine housing is provided.
In the first heat shield plate portion and the second heat shield plate portion, the first end portion of the first heat shield plate portion and the second end portion of the second heat shield plate portion are the turbine housing and the bearing housing. At least one of the first surface of the first end portion or the second surface of the second end portion facing each other has a recess.

According to the configuration of (5) above, at least one of the surfaces (first surface and second surface) facing each other is recessed in the first end portion and the second end portion sandwiched between the turbine housing and the bearing housing. Therefore, the area in which the first surface and the second surface are in contact with each other can be reduced by the recess. This makes it possible to suppress heat transfer from one of the first end or the second end to the other. Therefore, it is possible to suppress the transfer of heat from the turbine housing to the bearing housing and improve the efficiency of the turbine.

(6) In some embodiments, in the configuration of (5) above,
The first surface of the first heat shield plate portion includes a first recess extending along either the circumferential direction or the radial direction.
The second surface of the second heat shield plate portion includes a second recess extending along the other side in the circumferential direction or the radial direction.

According to the configuration of (6) above, the first surface of the first heat shield plate portion has the first recessed portion having a different extending direction from the second recessed portion provided on the second surface of the second heat shield plate portion. .. Therefore, at the first end portion and the second end portion sandwiched between the turbine housing and the bearing housing, the area where the first surface and the second surface are in contact with each other can be effectively reduced. Therefore, the transfer of heat from the turbine housing to the bearing housing can be further suppressed.

(7) In some embodiments, in any one of the above configurations (4) to (6),
A heat insulating material provided in the gap is provided.

According to the configuration (7) above, by providing a heat insulating material in the gap between the first heat shield plate portion and the second heat shield plate portion, heat from one heat shield plate portion to the other heat shield plate portion is provided. Can effectively suppress the movement of. Therefore, the effect of suppressing heat dissipation of exhaust gas can be improved.

(8) In some embodiments, in any one of the above configurations (4) to (7),
A bearing housing provided in the axial direction opposite to the outlet portion of the turbine housing is provided.
In the first heat shield plate portion and the second heat shield plate portion, the first end portion of the first heat shield plate portion and the second end portion of the second heat shield plate portion are the turbine housing and the bearing housing. It is sandwiched and fixed between
Between at least a part of the first heat shield plate portion excluding the first end portion and at least a part of the second heat shield plate portion excluding the second end portion. The gap is formed.

According to the configuration of (8) above, the first heat shield plate portion and the second heat shield plate portion are at least a part of a portion excluding the first end portion and the second end portion sandwiched between the turbine housing and the bearing housing. A gap is formed in. As a result, a gap is formed in each heat shield plate portion that is easily exposed to the exhaust gas flowing through the scroll flow path, the back surface of the turbine impeller, and the like, so that the heat dissipation of the exhaust gas can be effectively suppressed.

(9) In some embodiments, in the configuration of (8) above,
The turbine includes a heat insulating material provided in the gap between the first heat shield plate portion and the second heat shield plate portion, and the first heat shield plate portion and the second heat shield plate portion are , The first end portion sandwiched between the turbine housing and the bearing housing and the end portions on the opposite side of the second end portion are connected to each other.

According to the configuration of (9) above, the heat insulating material provided in the gap between the first heat shield plate portion and the second heat shield plate portion is formed between the first end portion and the end portions on the opposite side to the second end portion. It is possible to suppress falling out from between, and it is possible to maintain a high heat dissipation suppressing effect.

(10) In some embodiments, in the configuration of (8) above,
Each of the first heat shield plate portion and the second heat shield plate portion has an end portion opposite to the first end portion or the second end portion sandwiched between the turbine housing and the bearing housing. It is a free end.

According to the configuration of (10) above, the end portion opposite to the first end portion or the second end portion sandwiched between the turbine housing and the bearing housing is a free end and is not restrained. Therefore, it is possible to allow thermal deformation of the first heat shield plate portion and the second heat shield plate portion due to the heat input of the exhaust gas, and reduce the thermal stress of the first heat shield plate portion and the second heat shield plate portion. The durability of the hot plate can be improved.

(11) In some embodiments, in any one of the above configurations (4) to (10),
The first heat shield plate portion is provided so as to face the scroll flow path at least partially.
The second heat shield plate portion is provided at least partially so as to face the back surface of the turbine impeller on the radial inside of the first heat shield plate portion.
In this case, the first heat shield plate portion may constitute the "throat forming portion" in the above (1) to (3).

Comparing the area facing the scroll flow path and the area facing the back surface of the turbine impeller, the area facing the scroll flow path before the exhaust gas is introduced into the turbine impeller is the heat that determines the amount of heat input from the exhaust gas. High transmission rate.
Therefore, as described in (11) above, the first heat shield plate portion is provided in the region facing the scroll flow path having a high heat transfer coefficient, and the second heat shield plate portion has a gap with respect to the first heat shield plate portion. By providing the hot plate portion, heat dissipation from the exhaust gas can be effectively suppressed.

(12) In some embodiments, in any one of the above configurations (4) to (10),
A heat shield coating is applied to at least one of the first heat shield plate portion and the second heat shield plate portion.

According to the configuration (12) above, the effect of suppressing heat dissipation of exhaust gas by the first heat shield plate portion and the second heat shield plate portion can be further enhanced, and the efficiency of the turbine can be improved.

(13) The turbocharger according to some embodiments of the present invention is
The turbine according to any one of (1) to (12) above, and
It has a compressor impeller and includes a compressor configured to be driven by the turbine.

According to the configuration of (13) above, as described in (1) to (12) above, the throat portion of the scroll flow path whose width in the axial direction is narrower than that of other portions faces the shroud side wall surface. The side wall surface of the hub can be formed by a throat forming portion different from the turbine housing. Therefore, even when the turbine is miniaturized, it is possible to facilitate the molding of the core forming the inner wall shape when casting the turbine housing, and it is possible to improve the moldability of the inner wall shape of the turbine housing.
Alternatively, as described in (4) above, the heat shield portion including the first heat shield plate portion and the second heat shield plate portion sandwiches at least one of the turbine impeller or the scroll flow path and serves as an outlet portion in the axial direction. Since it is located on the opposite side, heat dissipation of exhaust gas flowing through the scroll flow path and the turbine impeller can be suppressed. Further, an intermediate layer is formed by sandwiching a gap at least partially between the first heat shield plate portion and the second heat shield plate portion, and heat is transferred from one heat shield plate portion to the other heat shield plate portion. Can be suppressed. Therefore, the efficiency of the turbine can be improved by suppressing the exhaust gas from radiating to the outside.

According to at least one embodiment of the present invention, it is possible to provide a turbine housing capable of improving the moldability of the inner wall shape of the turbine housing by casting while promoting the miniaturization of the turbocharger, and a turbocharger including the same.

It is a schematic cross-sectional view which shows the whole structure of the turbocharger to which the turbine which concerns on one Embodiment is applied. It is an enlarged view of the vicinity of a turbine in the turbocharger of FIG. It is a figure which shows the turbine which provided the heat shield part which concerns on some Embodiments. It is a figure which shows the form of the heat-shielding part which has the heat insulating material which concerns on some embodiments. It is a figure which shows the modification of the heat shield part which concerns on some Embodiments. It is a figure which shows the other modification of the heat shield part which concerns on some Embodiments. 3 is an enlarged view of the vicinity of the first end portion and the second end portion in FIGS. 3 to 6. It is a perspective view for demonstrating the form of the concave part in the end part of the heat-shielding part which concerns on some embodiments.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. Absent.

(First Embodiment)
First, with reference to FIG. 1, the overall configuration of the turbocharger to which the turbine according to some embodiments is applied will be described. FIG. 1 is a diagram showing a schematic configuration of a turbocharger 1 to which the turbine 31 according to the embodiment is applied.

As shown in FIG. 1, the turbocharger 1 according to some embodiments of the present invention includes a compressor housing 20 and a turbine housing 30 arranged so as to sandwich a bearing housing 10. The rotating shaft 12 has a turbine impeller 32 housed in the turbine housing 30 at one end and a compressor impeller 22 housed in the compressor housing 20 at the other end. The rotary shaft 12, the turbine impeller 32, and the compressor impeller 22 are connected or coupled to each other to form an integral body as a whole, and the rotary shaft 12 is rotatably supported by a bearing 14 provided in the bearing housing 10.

The compressor housing 20 is formed with an air inlet portion 24 for taking air into the compressor housing 20. The air compressed by the rotation of the compressor impeller 22 passes through the diffuser flow path 26 and the compressor scroll flow path 28, and is discharged to the outside of the compressor housing 20 via an air outlet (not shown).

The turbine housing 30 is formed with a gas inlet portion (not shown) for taking exhaust gas from the engine (not shown) into the turbine housing 30, and the gas inlet portion is an exhaust manifold of the engine (not shown). ) Can be connected. Further, in the turbine housing 30, a spiral scroll flow path 36 is provided on the outer peripheral portion of the turbine impeller 32 so as to cover the turbine impeller 32. The scroll flow path 36 communicates with the gas inlet portion and is formed so as to take in the exhaust gas inside. Inside the scroll flow path 36 in the radial direction, a throat portion 38 for guiding the exhaust gas from the scroll flow path 36 to the turbine impeller 32 is provided. The throat portion 38 is a portion of the scroll flow path 36 whose width in the axial direction is narrower than that of other portions. The exhaust gas that has passed through the turbine impeller 32 is discharged to the outside of the turbine housing 30 via the gas outlet portion 39.
As described above, the turbocharger 1 rotationally drives the turbine impeller 32 using the exhaust gas of the engine, transmits the rotational force to the compressor impeller 22 via the rotating shaft 12, and centrifuges the air entering the compressor housing 20. It can be compressed by force and supplied to the engine.

FIG. 2 is an enlarged view of the vicinity of the turbine 31 in the turbocharger 1. As shown in FIG. 2, in some embodiments, the turbine 31 includes a throat forming portion 41 provided as a separate member from the turbine housing 30, and the throat forming portion 41 scrolls out of the turbine housing 30 in the axial direction. The throat portion 38 of the flow path 36 is provided so as to face the portion forming the shroud side wall surface 43, and forms the hub side wall surface 44 of the throat portion 38.

When both the shroud side wall surface 43 and the hub side wall surface 44 of the throat portion 38 are formed by the turbine housing 30, the throat portion 38 having a relatively narrow width is formed depending on the shape of the inner wall of the turbine housing 30. Since the turbine housing 30 is usually molded by casting, the feasibility of the core forming the inner wall shape of the turbine housing 30 is important. However, if the turbocharger 1 is miniaturized due to recent demands, it becomes difficult to mold the core forming the inner wall shape of the turbine housing 30, and the feasibility of the core may decrease. In particular, since the throat portion 38 of the scroll flow path 36 is narrower than other portions, the feasibility of the core due to the miniaturization of the turbocharger 1 tends to be a problem.

The core forming the inner wall shape of the scroll flow path 36 has a constriction in the vicinity of the throat portion 38. When both the shroud side wall surface 43 and the hub side wall surface 44 of the throat portion 38 are formed by the turbine housing, the minimum width of the constriction in the axial direction of the core is the distance L1 between the shroud side wall surface 43 and the hub side wall surface 44. ..
On the other hand, according to the present embodiment, in the throat portion 38, the hub side wall surface 44 facing the shroud side wall surface 43 can be formed by the throat forming portion 41 which is a member different from the turbine housing 30. In this case, only the shroud side wall surface 43 of the throat portion 38 needs to be formed depending on the shape of the inner wall of the turbine housing 30, and the minimum width of the core in the axial direction can be set to L2, which is larger than L1.

As described above, according to the present embodiment, even if the turbine 31 tends to be miniaturized, it is possible to facilitate the molding of the core forming the inner wall shape at the time of casting the turbine housing 30. Therefore, the moldability of the inner wall shape of the turbine housing 30 can be improved. Further, by increasing the minimum width of the core constriction in the vicinity of the throat portion 38, the strength of the core itself repeatedly used for casting can be increased.

In some embodiments, as shown in FIG. 2, the throat forming portion 41 has a first portion 47 forming the hub side wall surface 44 of the throat portion 38 and a turbine impeller radially inside the first portion 47. Includes a second portion 48 facing the back surface 33 of the 32.

According to the present embodiment, since the throat forming portion 41 includes a first portion 47 forming the hub side wall surface 44 of the throat portion 38 and a second portion 48 facing the back surface 33 of the turbine impeller 32, the throat forming portion 41 Can also be used as a portion of the turbine impeller 32 facing the back surface 33. With such a simple structure, the establishment of the core in the casting of the turbine housing 30 can be improved, and the heat dissipation of the exhaust gas on the back surface 33 side of the turbine impeller 32 can be suppressed.

Further, in some embodiments, the throat forming portion 41 includes a plate member forming the hub side wall surface 44 of the throat portion 38. In the exemplary embodiment of FIG. 2, the throat forming portion 41 is formed by a member having a plate shape as a whole, and the radially outer end portion 46 of the throat forming portion 41 is the holding portion 37 of the turbine housing 30 and the bearing housing 10. It is sandwiched and fixed between the sandwiching portions 18. The turbine housing 30 and the bearing housing 10 are connected by fastening the sandwiching portions (18, 37) with the clamp 16.

According to the present embodiment, since a plate-shaped member can be adopted for the throat forming portion 41, the hub side wall surface 44 of the throat portion 38 can be formed by using a sheet metal product. The sheet metal product includes, for example, a commonly used back plate as shown in the specific example of FIG.

(Second Embodiment)
The second embodiment described below is different from the problem solved by the first embodiment described above (improvement of moldability of the inner wall shape of the turbine housing 30), and the turbine 31 is produced by suppressing heat dissipation of exhaust gas. This is to solve the problem of improving the efficiency of the turbine. The configuration of the heat shield 50 according to the second embodiment will be described with reference to FIGS. 3 to 6. FIG. 3 is a diagram showing a turbine 31 provided with a heat shield 50 according to some embodiments. FIG. 4 is a diagram showing a mode of a heat shield portion 50 having a heat insulating material 59 according to some embodiments. FIG. 5 is a diagram showing a modified example of the heat shield portion 50 according to some embodiments. FIG. 6 is a diagram showing another modification of the heat shield 50 according to some embodiments.

In some embodiments, as shown in FIG. 3, the turbine impeller 32 or the scroll flow path 36 communicating with the turbine impeller 32 is located on the opposite side of the gas outlet portion 39 in the axial direction with respect to at least one of them. The heat shield portion 50 is provided, and the heat shield portion 50 is arranged with a gap 54 between the first heat shield plate portion 51 and the first heat shield plate portion 51 at least partially. The hot plate portion 52 and the like are included.
In one embodiment of FIG. 3, the first heat shield plate portion 51 is provided on the side opposite to the gas outlet portion 39 in the axial direction with the scroll flow path 36 interposed therebetween, and the second heat shield plate portion 52 is provided on the turbine impeller 32. Is also provided on the opposite side of the gas outlet 39. Further, each heat shield plate portion (51, 52) is arranged so that a gap 54 is formed in a region on the inner diameter side of the first heat shield plate portion 51 and on the outer diameter side of the second heat shield plate portion 52.

According to the present embodiment, the heat shield portion 50 including the first heat shield plate portion 51 and the second heat shield plate portion 52 sandwiches at least one of the turbine impeller 32 and the scroll flow path 36 and is a gas outlet portion in the axial direction. Since it is located on the opposite side of 39, heat dissipation of exhaust gas flowing through the scroll flow path 36 and the turbine impeller 32 can be suppressed. Further, an intermediate layer is formed by sandwiching a gap 54 at least partially between the first heat shield plate portion 51 and the second heat shield plate portion 52, and from one heat shield plate portion to the other heat shield plate portion. It is possible to suppress the transfer of heat. Therefore, the efficiency of the turbine 31 can be improved by suppressing the exhaust gas from radiating to the outside.

In some embodiments, as also shown in FIG. 3, a bearing housing 10 is provided on the side opposite to the gas outlet 39 of the turbine housing 30 in the axial direction, and the first heat shield 51 and the second heat shield 51 and the second are provided. In the heat shield plate portion 52, the first end portion 57 of the first heat shield plate portion 51 and the second end portion 58 of the second heat shield plate portion 52 are sandwiched and fixed between the turbine housing 30 and the bearing housing 10. , Between at least a part of the first heat shield plate portion 51 excluding the first end portion 57 and at least a part of the second heat shield plate portion 52 excluding the second end portion 58. A gap 54 is formed.
According to the present embodiment, a gap 54 is formed in each of the heat shield plates (51, 52) at a portion easily exposed to the exhaust gas flowing through the scroll flow path 36, the back surface 33 of the turbine impeller 32, and the like, which is effective. The heat dissipation of exhaust gas can be suppressed.

Further, each of the first heat shield plate portion 51 and the second heat shield plate portion 52 is an end opposite to the first end portion 57 or the second end portion 58 sandwiched between the turbine housing 30 and the bearing housing 10. The part (65,66) is the free end.
As a result, the heat deformation of the first heat shield plate portion 51 and the second heat shield plate portion 52 due to the heat input of the exhaust gas is allowed, and the thermal stress of the first heat shield plate portion 51 and the second heat shield plate portion 52 is reduced. Therefore, the durability of each heat shield plate portion (51, 52) can be improved.

As shown in FIG. 4, the turbine 31 according to some embodiments includes a heat insulating material 59 provided in the gap 54. According to this embodiment, heat transfer from one heat shield plate portion to the other heat shield plate portion can be effectively suppressed. Further, in the gap 54 provided between the first heat shield plate portion 51 and the second heat shield plate portion 52, heat transfer due to radiation is likely to occur, and from the viewpoint of suppressing this, the heat insulating material 59 to the gap 54 Hiring is effective. As a result, according to the present embodiment, an excellent heat dissipation suppressing effect of exhaust gas can be obtained.

Further, in one embodiment, as illustrated in FIG. 4, a heat insulating material 59 provided in the gap 54 between the first heat shield plate portion 51 and the second heat shield plate portion 52 is provided, and the first heat shield is provided. The plate portion 51 and the second heat shield plate portion 52 have ends (65, 66) opposite to the first end portion 57 and the second end portion 58 sandwiched between the turbine housing 30 and the bearing housing 10. Connected to each other.

According to the present embodiment, the heat insulating material 59 provided in the gap 54 between the first heat shield plate portion 51 and the second heat shield plate portion 52 is on the opposite side of the first end portion 57 and the second end portion 58. It is possible to prevent the ends (65, 66) from falling off from each other, and it is possible to maintain a high heat dissipation suppressing effect.

In the exemplary embodiment shown in FIGS. 3 and 4, the first heat shield plate portion 51 is composed of a member different from the second heat shield plate portion 52, but the heat shield portion 50 is specific. The configuration is not limited to this example. That is, as in the modified example shown in FIG. 5, the heat shield portion 50 including the first heat shield plate portion 51 and the second heat shield plate portion 52 may be configured by bending one plate-shaped member. Also in this case, the ends (65, 66) of the first heat shield plate portion 51 and the second heat shield plate portion 52 are connected to each other as in the embodiment shown in FIG.

In some embodiments, at least one of the first heat shield plate portion 51 or the second heat shield plate portion 52 may be provided with a heat shield coating. By forming a film forming a heat shield layer on each of the heat shield plate portions (51, 52), a higher heat dissipation suppressing effect can be obtained.

In some embodiments, as shown in FIGS. 3-5, the first heat shield 51 is provided at least partially facing the scroll flow path 36, and the second heat shield 52 is At least partially, it is provided so as to face the back surface 33 of the turbine impeller 32 on the radial inside of the first heat shield plate portion 51.

Comparing the region facing the scroll flow path 36 with the region facing the back surface 33 of the turbine impeller 32, the region facing the scroll flow path 36 before the exhaust gas is introduced into the turbine impeller 32 is from the exhaust gas. The heat transfer coefficient that determines the amount of heat input is high.
Therefore, as in the present embodiment, the first heat shield plate portion 51 is provided in the region facing the scroll flow path 36 having a high heat transfer coefficient, and a gap 54 is provided with respect to the first heat shield plate portion 51. By providing the second heat shield plate portion 52, heat dissipation from the exhaust gas can be effectively suppressed.

In this embodiment, the first heat shield plate portion 51 may constitute the throat forming portion 41 in the first embodiment. 3 to 5 show an example in which the first heat shield plate portion 51 constitutes the hub side wall surface 44 of the throat portion 38 as the throat forming portion 41 instead of the turbine housing 30. According to such an embodiment, not only can the effect of suppressing heat dissipation of the exhaust gas be effectively enjoyed, but also the feasibility of the core is improved when the turbine housing 30 is cast, as described in the first embodiment. It is also possible to promote the miniaturization of the turbine 31.

Further, in one embodiment, as shown in FIG. 3, the first heat shield plate portion 51 is provided at least partially so as to face the scroll flow path 36, and the second heat shield plate portion 52 is at least partially. The first end portion 57 and the first end portion 57 sandwiched between the turbine housing 30 and the bearing housing 10 are provided so as to face the back surface 33 of the turbine impeller 32 on the radial inside of the first heat shield plate portion 51. The ends (65, 66) opposite to the second end 58 are free ends.

Since the exhaust gas is relatively hot in the region facing the scroll flow path 36 than in the region facing the back surface 33 of the turbine impeller 32, there is a difference in the method of thermal deformation of the heat shield 50 in both regions. .. Therefore, when the heat shields 50 are provided in both regions, it is desirable to adopt a configuration that suppresses interference with the turbine impeller 32 in consideration of the difference in the method of thermal deformation.
In this regard, according to the present embodiment, the first heat shield plate portion 51 can be provided in the region where the temperature is relatively high, and the second heat shield plate portion 52 can be provided in the region where the temperature is relatively low. Further, since the ends 65 and 66 are not constrained and are free ends, the first heat shield plate portion 51 and the second heat shield plate portion 52 can absorb different methods of thermal deformation depending on the exhaust gas temperature. Therefore, with the simple configuration as described above, it is possible to suppress interference with the turbine impeller 32 due to thermal deformation of each heat shield plate portion (51, 52) while effectively suppressing heat dissipation of exhaust gas.

Although some configurations according to the second embodiment have been described above with reference to FIGS. 3 to 5, the second embodiment has the first heat shield plate portion as illustrated in FIGS. 3 to 5. It is not limited to the form in which the hub side wall surface 44 of the throat portion 38 is formed by the 51, and is also applicable to the case where the turbine housing 30 itself forms the hub side wall surface 44 of the throat portion 38. In this case, as illustrated in FIG. 6, both the first heat shield plate portion 51 and the second heat shield plate portion 52 are provided with a gap 54 so as to face the back surface 33 side of the turbine impeller 32. May be good.

Hereinafter, the structures of the first end portion 57 of the first heat shield plate portion 51 and the second end portion 58 of the second heat shield plate portion 52 according to some embodiments will be described with reference to FIGS. 7 and 8. explain. FIG. 7 is an enlarged view of the vicinity of the first end portion 57 and the second end portion 58 in FIGS. 3 to 6. FIG. 8 is a perspective view for showing the form of the recess in the end portion (57, 58) of the heat shield portion 50 according to some embodiments. Some of the embodiments described below are applicable to each configuration for the second embodiment described above.

In some embodiments, as shown in FIGS. 7 and 8, the first heat shield plate portion 51 and the second heat shield plate portion 52 are the first end portion 57 and the second heat shield plate portion 51 of the first heat shield plate portion 51. The second end 58 of the heat shield 52 is sandwiched and fixed between the turbine housing 30 and the bearing housing 10, and the first surface 61 of the first end 57 or the second surface 58 of the second end 58 facing each other. At least one of 62 has a recess.

As shown in FIG. 7, in the portion where the first end portion 57 of the first heat shield plate portion 51 and the second end portion 58 of the second heat shield plate portion 52 are sandwiched, the sandwiching portion 37 and the second portion of the turbine housing 30 are sandwiched. The first end 57 comes into contact with the holding portion 18 and the second end 58 of the bearing housing 10. Further, the first surface 61 of the first end portion 57 and the second surface 62 of the second end portion 58 also come into contact with each other. Therefore, the heat from the turbine housing 30 side easily moves to the bearing housing 10 side via the sandwiching portion (18,37) and each end portion (57,58), which may lead to a decrease in the efficiency of the turbine 31. ..
In this regard, according to the present embodiment, at the first end portion 57 and the second end portion 58 sandwiched between the turbine housing 30 and the bearing housing 10, the surfaces facing each other (first surface 61 and second surface 62). ) Has a recess, so that the area where the first surface 61 and the second surface 62 are in contact with each other can be reduced by the recess. As a result, it is possible to suppress heat transfer from one of the first end portion 57 or the second end portion 58 to the other. Therefore, it is possible to suppress the transfer of heat from the turbine housing 30 to the bearing housing 10 and improve the efficiency of the turbine 31.
The third surface 63 of the first end portion 57 makes a metal touch with the inner wall 73 of the holding portion 37 of the turbine housing 30, and the fourth surface 64 of the second end portion 58 is the inner wall 74 of the holding portion 18 of the bearing housing 10. By making the metal touch with the exhaust gas, even if the recess is provided on at least one of the first surface 61 and the second surface 62, the leakage of the exhaust gas to the outside can be suppressed.

In one embodiment, as shown in FIG. 8, the first surface 61 of the first heat shield plate portion 51 includes a first recess 71 extending along one of the circumferential direction and the radial direction, and includes a second heat shield. The second surface 62 of the plate portion 52 includes a second recess 72 extending along the other in the circumferential direction or the radial direction. In the example of FIG. 8, a plurality of first recesses 71 in which the first surface 61 extends in the radial direction are included in the circumferential direction, and one second recess 72 in which the second surface 62 extends in the circumferential direction is included in the radial direction. I'm out.

When the first end portion 57 and the second end portion 58 are sandwiched, when the first surface 61 and the second surface 62 come into contact with each other, the portion that actually contacts is the second surface 62 of the same figure in the example of FIG. As shown by the diagonal lines, the contact area with each other can be reduced. As described above, according to the present embodiment, the first surface 61 of the first heat shield plate portion 51 has a extending direction with the second recess 72 provided on the second surface 62 of the second heat shield plate portion 52. By having the different first recesses 71, the area where the first surface 61 and the second surface 62 are in contact with each other can be effectively reduced. Therefore, the transfer of heat from the turbine housing 30 to the bearing housing 10 can be further suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes a modified form of the above-described embodiments and a combination of these embodiments as appropriate.

In the present specification, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial". Strictly represents not only such an arrangement, but also a tolerance or a state of relative displacement at an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the state of existence.
Further, in the present specification, the expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also within a range in which the same effect can be obtained. , The shape including the uneven portion, the chamfered portion, etc. shall also be represented.
Further, in the present specification, the expression "comprising", "including", or "having" one component is not an exclusive expression excluding the existence of another component.

1 Turbocharger 10 Bearing housing 12 Rotating shaft 14 Bearing 16 Clamp 18 Holding part 20 Compressor housing 22 Compressor impeller 24 Air inlet part 26 Diffuser flow path 28 Scroll flow path 30 Turbine housing 31 Turbine 32 Turbine impeller 33 Back surface 36 Scroll flow path 37 Holding Part 38 Throat part 39 Gas outlet part 41 Throat forming part 43 Shroud side wall surface 44 Hub side wall surface 46 End part 47 First part 48 Second part 50 Heat shield part 51 First heat shield plate part 52 Second heat shield plate part 54 Gap 57 1st end 58 2nd end 59 Insulation 61 1st surface 62 2nd surface 71 1st recess 72 2nd recess

Claims (8)

Turbine impeller and
A turbine housing provided so as to cover the turbine impeller and having an outlet portion for exhausting exhaust gas after passing through the turbine impeller.
A heat shield portion located on the side opposite to the outlet portion in the axial direction is provided with at least one of the turbine impeller or a scroll flow path communicating with the turbine impeller.
The heat shield is
In the axial direction, the turbine housing is provided facing the scroll flow path so as to face the portion of the turbine housing that forms the shroud side wall surface of the throat portion of the scroll flow path, and the hub side wall surface of the throat portion is provided. The first heat shield to be formed and
A second heat shield plate portion that is at least partially arranged with a gap between the first heat shield plate portion and the first heat shield plate portion.
Including
A bearing housing provided in the axial direction opposite to the outlet portion of the turbine housing is provided.
In the first heat shield plate portion and the second heat shield plate portion, the first end portion of the first heat shield plate portion and the second end portion of the second heat shield plate portion are the turbine housing and the bearing housing. At least one of the first surface of the first end and the second surface of the second end facing each other is recessed.
The first surface of the first heat shield plate portion includes a first recess extending along either the circumferential direction or the radial direction.
A turbine characterized in that the second surface of the second heat shield plate portion includes a second recess extending along the other in the circumferential direction or the radial direction. The turbine according to claim 1, further comprising a heat insulating material provided in the gap. A bearing housing provided in the axial direction opposite to the outlet portion of the turbine housing is provided.
In the first heat shield plate portion and the second heat shield plate portion, the first end portion of the first heat shield plate portion and the second end portion of the second heat shield plate portion are the turbine housing and the bearing housing. It is sandwiched and fixed between
Between at least a part of the first heat shield plate portion excluding the first end portion and at least a part of the second heat shield plate portion excluding the second end portion. The turbine according to any one of claims 1 to 2 , wherein a gap is formed. A heat insulating material provided in the gap between the first heat shield plate portion and the second heat shield plate portion is provided.
In the first heat shield plate portion and the second heat shield plate portion, the first end portion sandwiched between the turbine housing and the bearing housing and the ends opposite to the second end portion are mutually opposite. The turbine according to claim 3 , wherein the turbine is connected. Each of the first heat shield plate portion and the second heat shield plate portion has an end portion opposite to the first end portion or the second end portion sandwiched between the turbine housing and the bearing housing. The turbine according to claim 3 , wherein the turbine has a free end. Any of claims 1 to 5 , wherein the second heat shield plate portion is provided at least partially so as to face the back surface of the turbine impeller on the radial inside of the first heat shield plate portion. The turbine according to one item. The turbine according to any one of claims 1 to 5 , wherein a heat shield coating is applied to at least one of the first heat shield plate portion and the second heat shield plate portion. The turbine according to any one of claims 1 to 7 .
A turbocharger comprising a compressor impeller and a compressor configured to be driven by the turbine.

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